6 people and luggage - you will need a minivan. You could also rent 2 cars instead, which may be cheaper than one minivan. We usually go to Disney every October. A full size car rental costs approximately $200 for 7-8 days. A minivan rental prices can be very varied - about $350-600 for same period of time. This assumes you do your homework and use codes and are willing to book/rebook when rental prices go down. Most of the lower prices occur much closer to your trip. I make a reservation and will rebook a new one and cancel other one as I get a better price. Lots of information here on discounted car rentals! Usually for a minivan, a great anytime code is Travelocity code with
Budget x474200. Look to add a coupon to get another $20-40 off.
Parking a Disney is $14 per day (per vehicle) so a minivan would be better, in my opinion, as everyone can ride for one parking fee. You are going to have to pay to get to and from the airport anyway. For a little more, you will have the flexibility to go to and from the parks when you want. You can also go to the grocery store as needed or save money by eating off site.
Check the Wyndham Bonnet Creek shuttle schedule. I remember the times as being quite limited, especially mid-day. If your kids are small, you may want to go back to the hotel for lunch/snacks, nap and/or swim. We really like the flexibility and hate feeling locked into a schedule, especially with kids.
With Disney, once you pay the $14, you can park in any park and come and go that day as you please without paying it again. We stay offsite to save money and get more space. We always figure in the price of the parking and the cost of the rental car (we always rent a car even if we stay on Disney property, but usually a smaller one).